bevy/examples/3d/3d_shapes.rs
Joona Aalto 54006b107b
Migrate meshes and materials to required components (#15524)
# Objective

A big step in the migration to required components: meshes and
materials!

## Solution

As per the [selected
proposal](https://hackmd.io/@bevy/required_components/%2Fj9-PnF-2QKK0on1KQ29UWQ):

- Deprecate `MaterialMesh2dBundle`, `MaterialMeshBundle`, and
`PbrBundle`.
- Add `Mesh2d` and `Mesh3d` components, which wrap a `Handle<Mesh>`.
- Add `MeshMaterial2d<M: Material2d>` and `MeshMaterial3d<M: Material>`,
which wrap a `Handle<M>`.
- Meshes *without* a mesh material should be rendered with a default
material. The existence of a material is determined by
`HasMaterial2d`/`HasMaterial3d`, which is required by
`MeshMaterial2d`/`MeshMaterial3d`. This gets around problems with the
generics.

Previously:

```rust
commands.spawn(MaterialMesh2dBundle {
    mesh: meshes.add(Circle::new(100.0)).into(),
    material: materials.add(Color::srgb(7.5, 0.0, 7.5)),
    transform: Transform::from_translation(Vec3::new(-200., 0., 0.)),
    ..default()
});
```

Now:

```rust
commands.spawn((
    Mesh2d(meshes.add(Circle::new(100.0))),
    MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))),
    Transform::from_translation(Vec3::new(-200., 0., 0.)),
));
```

If the mesh material is missing, previously nothing was rendered. Now,
it renders a white default `ColorMaterial` in 2D and a
`StandardMaterial` in 3D (this can be overridden). Below, only every
other entity has a material:

![Näyttökuva 2024-09-29
181746](https://github.com/user-attachments/assets/5c8be029-d2fe-4b8c-ae89-17a72ff82c9a)

![Näyttökuva 2024-09-29
181918](https://github.com/user-attachments/assets/58adbc55-5a1e-4c7d-a2c7-ed456227b909)

Why white? This is still open for discussion, but I think white makes
sense for a *default* material, while *invalid* asset handles pointing
to nothing should have something like a pink material to indicate that
something is broken (I don't handle that in this PR yet). This is kind
of a mix of Godot and Unity: Godot just renders a white material for
non-existent materials, while Unity renders nothing when no materials
exist, but renders pink for invalid materials. I can also change the
default material to pink if that is preferable though.

## Testing

I ran some 2D and 3D examples to test if anything changed visually. I
have not tested all examples or features yet however. If anyone wants to
test more extensively, it would be appreciated!

## Implementation Notes

- The relationship between `bevy_render` and `bevy_pbr` is weird here.
`bevy_render` needs `Mesh3d` for its own systems, but `bevy_pbr` has all
of the material logic, and `bevy_render` doesn't depend on it. I feel
like the two crates should be refactored in some way, but I think that's
out of scope for this PR.
- I didn't migrate meshlets to required components yet. That can
probably be done in a follow-up, as this is already a huge PR.
- It is becoming increasingly clear to me that we really, *really* want
to disallow raw asset handles as components. They caused me a *ton* of
headache here already, and it took me a long time to find every place
that queried for them or inserted them directly on entities, since there
were no compiler errors for it. If we don't remove the `Component`
derive, I expect raw asset handles to be a *huge* footgun for users as
we transition to wrapper components, especially as handles as components
have been the norm so far. I personally consider this to be a blocker
for 0.15: we need to migrate to wrapper components for asset handles
everywhere, and remove the `Component` derive. Also see
https://github.com/bevyengine/bevy/issues/14124.

---

## Migration Guide

Asset handles for meshes and mesh materials must now be wrapped in the
`Mesh2d` and `MeshMaterial2d` or `Mesh3d` and `MeshMaterial3d`
components for 2D and 3D respectively. Raw handles as components no
longer render meshes.

Additionally, `MaterialMesh2dBundle`, `MaterialMeshBundle`, and
`PbrBundle` have been deprecated. Instead, use the mesh and material
components directly.

Previously:

```rust
commands.spawn(MaterialMesh2dBundle {
    mesh: meshes.add(Circle::new(100.0)).into(),
    material: materials.add(Color::srgb(7.5, 0.0, 7.5)),
    transform: Transform::from_translation(Vec3::new(-200., 0., 0.)),
    ..default()
});
```

Now:

```rust
commands.spawn((
    Mesh2d(meshes.add(Circle::new(100.0))),
    MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))),
    Transform::from_translation(Vec3::new(-200., 0., 0.)),
));
```

If the mesh material is missing, a white default material is now used.
Previously, nothing was rendered if the material was missing.

The `WithMesh2d` and `WithMesh3d` query filter type aliases have also
been removed. Simply use `With<Mesh2d>` or `With<Mesh3d>`.

---------

Co-authored-by: Tim Blackbird <justthecooldude@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-10-01 21:33:17 +00:00

190 lines
5.7 KiB
Rust

//! This example demonstrates the built-in 3d shapes in Bevy.
//! The scene includes a patterned texture and a rotation for visualizing the normals and UVs.
//!
//! You can toggle wireframes with the space bar except on wasm. Wasm does not support
//! `POLYGON_MODE_LINE` on the gpu.
use std::f32::consts::PI;
#[cfg(not(target_arch = "wasm32"))]
use bevy::pbr::wireframe::{WireframeConfig, WireframePlugin};
use bevy::{
color::palettes::basic::SILVER,
prelude::*,
render::{
render_asset::RenderAssetUsages,
render_resource::{Extent3d, TextureDimension, TextureFormat},
},
};
fn main() {
App::new()
.add_plugins((
DefaultPlugins.set(ImagePlugin::default_nearest()),
#[cfg(not(target_arch = "wasm32"))]
WireframePlugin,
))
.add_systems(Startup, setup)
.add_systems(
Update,
(
rotate,
#[cfg(not(target_arch = "wasm32"))]
toggle_wireframe,
),
)
.run();
}
/// A marker component for our shapes so we can query them separately from the ground plane
#[derive(Component)]
struct Shape;
const SHAPES_X_EXTENT: f32 = 14.0;
const EXTRUSION_X_EXTENT: f32 = 16.0;
const Z_EXTENT: f32 = 5.0;
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut images: ResMut<Assets<Image>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
let debug_material = materials.add(StandardMaterial {
base_color_texture: Some(images.add(uv_debug_texture())),
..default()
});
let shapes = [
meshes.add(Cuboid::default()),
meshes.add(Tetrahedron::default()),
meshes.add(Capsule3d::default()),
meshes.add(Torus::default()),
meshes.add(Cylinder::default()),
meshes.add(Cone::default()),
meshes.add(ConicalFrustum::default()),
meshes.add(Sphere::default().mesh().ico(5).unwrap()),
meshes.add(Sphere::default().mesh().uv(32, 18)),
];
let extrusions = [
meshes.add(Extrusion::new(Rectangle::default(), 1.)),
meshes.add(Extrusion::new(Capsule2d::default(), 1.)),
meshes.add(Extrusion::new(Annulus::default(), 1.)),
meshes.add(Extrusion::new(Circle::default(), 1.)),
meshes.add(Extrusion::new(Ellipse::default(), 1.)),
meshes.add(Extrusion::new(RegularPolygon::default(), 1.)),
meshes.add(Extrusion::new(Triangle2d::default(), 1.)),
];
let num_shapes = shapes.len();
for (i, shape) in shapes.into_iter().enumerate() {
commands.spawn((
Mesh3d(shape),
MeshMaterial3d(debug_material.clone()),
Transform::from_xyz(
-SHAPES_X_EXTENT / 2. + i as f32 / (num_shapes - 1) as f32 * SHAPES_X_EXTENT,
2.0,
Z_EXTENT / 2.,
)
.with_rotation(Quat::from_rotation_x(-PI / 4.)),
Shape,
));
}
let num_extrusions = extrusions.len();
for (i, shape) in extrusions.into_iter().enumerate() {
commands.spawn((
Mesh3d(shape),
MeshMaterial3d(debug_material.clone()),
Transform::from_xyz(
-EXTRUSION_X_EXTENT / 2.
+ i as f32 / (num_extrusions - 1) as f32 * EXTRUSION_X_EXTENT,
2.0,
-Z_EXTENT / 2.,
)
.with_rotation(Quat::from_rotation_x(-PI / 4.)),
Shape,
));
}
commands.spawn((
PointLight {
shadows_enabled: true,
intensity: 10_000_000.,
range: 100.0,
shadow_depth_bias: 0.2,
..default()
},
Transform::from_xyz(8.0, 16.0, 8.0),
));
// ground plane
commands.spawn((
Mesh3d(meshes.add(Plane3d::default().mesh().size(50.0, 50.0).subdivisions(10))),
MeshMaterial3d(materials.add(Color::from(SILVER))),
));
commands.spawn(Camera3dBundle {
transform: Transform::from_xyz(0.0, 7., 14.0).looking_at(Vec3::new(0., 1., 0.), Vec3::Y),
..default()
});
#[cfg(not(target_arch = "wasm32"))]
commands.spawn(
TextBundle::from_section("Press space to toggle wireframes", TextStyle::default())
.with_style(Style {
position_type: PositionType::Absolute,
top: Val::Px(12.0),
left: Val::Px(12.0),
..default()
}),
);
}
fn rotate(mut query: Query<&mut Transform, With<Shape>>, time: Res<Time>) {
for mut transform in &mut query {
transform.rotate_y(time.delta_seconds() / 2.);
}
}
/// Creates a colorful test pattern
fn uv_debug_texture() -> Image {
const TEXTURE_SIZE: usize = 8;
let mut palette: [u8; 32] = [
255, 102, 159, 255, 255, 159, 102, 255, 236, 255, 102, 255, 121, 255, 102, 255, 102, 255,
198, 255, 102, 198, 255, 255, 121, 102, 255, 255, 236, 102, 255, 255,
];
let mut texture_data = [0; TEXTURE_SIZE * TEXTURE_SIZE * 4];
for y in 0..TEXTURE_SIZE {
let offset = TEXTURE_SIZE * y * 4;
texture_data[offset..(offset + TEXTURE_SIZE * 4)].copy_from_slice(&palette);
palette.rotate_right(4);
}
Image::new_fill(
Extent3d {
width: TEXTURE_SIZE as u32,
height: TEXTURE_SIZE as u32,
depth_or_array_layers: 1,
},
TextureDimension::D2,
&texture_data,
TextureFormat::Rgba8UnormSrgb,
RenderAssetUsages::RENDER_WORLD,
)
}
#[cfg(not(target_arch = "wasm32"))]
fn toggle_wireframe(
mut wireframe_config: ResMut<WireframeConfig>,
keyboard: Res<ButtonInput<KeyCode>>,
) {
if keyboard.just_pressed(KeyCode::Space) {
wireframe_config.global = !wireframe_config.global;
}
}